A harder clay surface makes adding detail easier.
Most sculpting clay is fairly soft, allowing you to push it around and create forms quickly. This softness is a benefit when roughing out a sculpture, but can be a problem when it comes time to add fine detail. Fortunately there are two easy ways to temporarily harden the surface of your clay, allowing you to do detail work without the risk of smearing. The first is through the use of powder, the second uses temperature.
Instructions
Baby Powder
1. Pour a small amount of baby powder into a bowl.
2. Load a fluffy makeup powder brush with a generous amount of baby powder.
3. Brush the powder against the clay using small, circular motions. You can be aggressive: the brush is too soft to damage the clay. This works well for water-based clay, and is adequate for oil-based clay.
Freezing
4. Purchase a can of compressed air from a computer shop. This product is typically used to clean electronics.
5. Hold the can upside-down.
6. Squeeze the trigger, allowing the liquid from the can to spray over the clay. This will rapidly cool and harden it for a short time.
7. Reapply this liquid as needed. This technique works well on oil-based clays, but can damage the surface of water-based clays by creating ice crystals in the clay.
